Twisted pair 4 conductors: the purpose of the four-conductor cable and crimping methods, the necessary tools and advice

When creating megabit LANs, a 4-core twisted pair cable is used. The bandwidth and number of wires of this type of cable is sufficient for patch cords of 10 or 100 Megabit networks. Working with the cable during the installation of the network, in addition to laying, includes crimping the twisted pair. In addition to the necessary tools for crimping, precision and accuracy are required from a specialist.

Twisted pair crimping scheme

The creation of wired LANs is regulated by the EIA / TIA-568 standard. There are two ways to crimp a twisted pair of 4 conductors - straight and cross (cross). If the cable will connect the system unit of the stationary computer and the router (switch), then direct crimping is applied - the conductors are located in the same order at both ends cable.

When connecting two routers or computers, cross crimping is used, in which the conductors at opposite ends of the cable are swapped in pairs - plain and striped. When crimping, 1, 2, 3 and 6 cores are used. It does not matter what color to attach to the contact number, the main thing is to follow the order when cross-crimping or direct crimping.

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Required tools

To perform the crimping operation of a 4-core cable, such tools and parts will be needed:

1. Directly the twisted pair itself 4 cores, which will be crimped;
2. Two RJ-45 connectors;
3. Special forceps (crimper) with 8P socket;
4. Stripping knife (stripper) or any other suitable cutting tool.

To control the quality and correctness of the crimping, it is worth purchasing a tester that will allow you to determine if the wires are mixed up when crimping the connector and the reliability of the crimp.

Cable compression process

When all the necessary materials and tools are prepared, you can proceed directly to crimping a twisted pair with 4 cores:

1. First, a piece of cable of the required length is separated from the coil. In this case, the cut itself does not have to be perfectly flat. Fitting the ends of the cores is done immediately before inserting the cores into the connectors.
2. After receiving a piece of cable of the required length, the ends of the cores are stripped from the insulation. Using a stripper or suitable cutting tools, make a cut around the outer insulation of the cable at a distance of 4-5 centimeters from the edge. The operation is carried out carefully to avoid damage to the inner veins.
3. Further, the twists are unwound, and the veins are arranged in a row, observing the order that is necessary for insertion into the connector. The extreme wiring (6 core) is slightly separated from the rest.
4. At a distance of 12-14 millimeters from the notch of the outer insulating shell, the internal wiring is trimmed. At the same time, make sure that the cut is strictly perpendicular to the axis of the wire.
5. The prepared wires are inserted into the connector itself. In this case, the first three wires go to the first three pins of the connector, and the fourth to the sixth. When inserting the wires inside, you need to ensure that their ends rest against the front wall of the connector.
6. The connector is clamped with crimping pliers (socket "8P") and squeezed until it clicks, after which the patch cord is released. And directly the connection itself is checked for strength. Pull the connector and cable in opposite directions with your hands. If the crimp is successful, then even a large force is not able to damage the connection.
7. The last step is the patch cord test. After crimping the two ends of the twisted pair, the connectors are inserted into the tester's sockets. When it is turned on, the LEDs will blink opposite the labels of the corresponding contacts. A green glow will indicate the normal state of the contacts and the integrity of the wire, and a red glow will indicate a cross or short circuit. Lack of light signal - the wire is not connected to the corresponding contact or its integrity inside the cable is broken.

In the case of crimping twisted pair 4 cores indication must correspond to 1, 2, 3 and 6 channels of the tester. The absence of a light reaction to other contacts is a normal phenomenon, since the connection was made only to the above contacts.

In the absence of a crimper, you can get by with a screwdriver to connect the wires to the connector. The preparatory stage in this case is the same as with the crimper. It is necessary to carefully remove the outer insulation from the cable, separate the cores and cut the ends strictly at an angle of 90 degrees to the cable axis. After that, the veins are inserted into the connector along the corresponding grooves, and the clamping of each wiring is carried out using a screwdriver. Such a connection will work, but in terms of the crimp quality, of course, it will be inferior to the crimper one.

Almost every user can crimp a twisted pair of 4 conductors without calling the master. It is only necessary to observe the correct order of actions and connect the wires to the contacts, depending on the purpose of the patch cord. When connecting a computer-switch - direct crimping, and when connecting devices of the same name (computer-computer or switch-switch) - cross.